body, ul, li, a{
    padding: 0;
    margin: 0;
    text-decoration: none;
    list-style: none;    
}

#container{
    position: relative;
    width: 520px;
    height: 280px;
    border: 2px solid #000;
    margin: 50px auto;
    overflow: hidden;
}
#list{
    position: absolute;
    width: 3640px;
    
}
#list img{
    float: left;
    width: 520px;
    height: 280px;
}

#buttons{
    display: inline-block;
    position: absolute;
    left: 50%;
    bottom: 20px;
    transform: translateX(-50%);
}
#buttons li{
    display: inline-block;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #ccc;
    cursor: pointer;
}
#buttons .active{
    background: orangered;
}

.arrow{
    /* display: none; */
    width: 40px;
    height: 40px;
    position: absolute;
    top: 50%;
    margin-top: -20px;
    color: #fff;
    font-size: 20px;
    font-weight: 600px;
    cursor: pointer;
    background: rgba(0, 0, 0, 0.3);
    text-align: center;
    line-height: 40px;
}
#container:hover .arrow {
    display: block;
  }
#prev{
    left: 0;
}
#next{
    right: 0;
}